Crashing

We've got these lovely boxes now, but the problem is we're running right over them! That's not very fair, we need to give these boxes a deadly upgrade! Like we did before, we need to detect when there is some sort of crossover. To the player, they're given the illusion that they've "collided" with something, but really, we're just calculating positions, and, if crossing over each other, we just say they've collided.

The new code:

import pygame
import time
import random

pygame.init()

display_width = 800
display_height = 600

black = (0,0,0)
white = (255,255,255)
red = (255,0,0)

car_width = 73

gameDisplay = pygame.display.set_mode((display_width,display_height))
pygame.display.set_caption('A bit Racey')
clock = pygame.time.Clock()

carImg = pygame.image.load('racecar.png')

def things(thingx, thingy, thingw, thingh, color):
    pygame.draw.rect(gameDisplay, color, [thingx, thingy, thingw, thingh])

def car(x,y):
    gameDisplay.blit(carImg,(x,y))

def text_objects(text, font):
    textSurface = font.render(text, True, black)
    return textSurface, textSurface.get_rect()

def message_display(text):
    largeText = pygame.font.Font('freesansbold.ttf',115)
    TextSurf, TextRect = text_objects(text, largeText)
    TextRect.center = ((display_width/2),(display_height/2))
    gameDisplay.blit(TextSurf, TextRect)

    pygame.display.update()

    time.sleep(2)

    game_loop()
    
    

def crash():
    message_display('You Crashed')
    
def game_loop():
    x = (display_width * 0.45)
    y = (display_height * 0.8)

    x_change = 0

    thing_startx = random.randrange(0, display_width)
    thing_starty = -600
    thing_speed = 7
    thing_width = 100
    thing_height = 100

    gameExit = False

    while not gameExit:

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()

            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_LEFT:
                    x_change = -5
                if event.key == pygame.K_RIGHT:
                    x_change = 5

            if event.type == pygame.KEYUP:
                if event.key == pygame.K_LEFT or event.key == pygame.K_RIGHT:
                    x_change = 0

        x += x_change
        gameDisplay.fill(white)

        # things(thingx, thingy, thingw, thingh, color)
        things(thing_startx, thing_starty, thing_width, thing_height, black)
        thing_starty += thing_speed
        car(x,y)

        if x > display_width - car_width or x < 0:
            crash()

        if thing_starty > display_height:
            thing_starty = 0 - thing_height
            thing_startx = random.randrange(0,display_width)

        ####
        if y < thing_starty+thing_height:
            print('y crossover')

            if x > thing_startx and x < thing_startx + thing_width or x+car_width > thing_startx and x + car_width < thing_startx+thing_width:
                print('x crossover')
                crash()
        ####
        
        pygame.display.update()
        clock.tick(60)


game_loop()
pygame.quit()
quit()

The major update here is:

        if y < thing_starty+thing_height:
            print('y crossover')

            if x > thing_startx and x < thing_startx + thing_width or x+car_width > thing_startx and x + car_width < thing_startx+thing_width:
                print('x crossover')
                crash()

So, we're asking if y, the car's top left, has crossed the object's y + height, meaning the bottom left. If it has, then, for logic sake, we print that y crossover has occurred. Now, this doesn't mean there's necessarily overlap, maybe the x coordinates are vastly different and we're on opposite sides. So, then we need to ask if the objects are anywhere within each other's boundaries.

The next tutorial: PyGame Score